Most pickup trucks currently in use carry with them a spare tire and wheel mounted underneath the bed of the truck, generally near or against the underside of the truck frame. Most commonly, the spare tire is mounted horizontally in this location and held in place by a simple straight bracket which runs underneath the spare tire. The spare tire is mounted to this bracket by some method such as bolting. The bracket is in turn bolted to the truck bed or frame.
Typically, the bracket is hinged from the frame at one end and bolted to the frame at the other end. The spare is removed from the truck by crawling under the truck and holding the spare and the bracket up while unbolting the bolted end of the bracket. This allows the bracket to be swung down to the ground, giving access to the bolts which secure the spare tire and wheel to the bracket. After the spare tire is unbolted from the bracket, it is manually dragged from under the truck.
This process has many disadvantages. Crawling under the truck and holding the spare tire up while unbolting the bracket will almost always result in soiled hands and clothing. It also may be physically impossible for an aged or handicapped person or a person lacking considerable physical strength, because the spare tire, wheel, and bracket can be very heavy. This process can also result in physical injury, because the spare tire is usually unwieldy, and if it drops unexpectedly, it will usually drop on the person trying to remove it from the vehicle. Finally, since removal from the truck is so troublesome, the spare tire will rarely have its air pressure checked, and it is often flat when most needed.
Several attempts have been made to devise a spare tire storage apparatus which makes the spare tire more easily accessible. Many of these still require crawling underneath the truck to release the tire or its carrier from the frame, or to manually pull the tire from underneath the truck. Some such devices require that the rear bumper of the truck or a portion of the rear bumper swing out of the way to allow the tire to pivot or slide from underneath the truck without being lowered.
Still others attempt to lower the tire first, such as by turning a bolt to screw the tire bracket downward or by turning a rack and pinion gear set to lower the tire. Then, the tire is usually swung out from under the vehicle manually. Regardless of the device, all known past attempts to solve the problems discussed here have resulted in devices which require some considerable strength and manual dexterity or which require significant modifications to the truck.